Scanner showing different SMART result over time

Question

This afternoon i checked a particular disk and it says no smart error, however tonight it shows mechanical disk warning, but later about an hour its back to no error state, whats causing the inconsistency? The report is crucial for me because its a pxe server..

Edit :

And oddly i didnt get a single email notification about this, i already checked all options in notification tab, just tested the email notification and it works fine...